After haven removed the air filter assembly I noticed there is a small bird cage fan (forward and left) of the filter housing. This fan on when the engine running or is it temp set?
It is there to cool down the engine and exhaust when not moving. You will hear it cycling on and off for a while after you shut it off.
Will need to check if it's working. what's the best way? I can hear the radiator fan cycling on/off but small one I haven't. Where is the temp sensor for it?
If you are hearing a fan after the engine is turned off, then you are hearing that fan, not the radiator. The temperature sensor for that one is above the muffler.
Copy. What I hear is definitely the radiator fan (more forward while driving. Any write ups on it (sub cooling fan) anywhere? Anyway to test sensor with volt meter? The fan available? P/N? How about the sensor P/N? Much appreciated
Both the fan and sensor have been discontinued for quite some time, but the part numbers are: 45121TA031 (Fan) and 88151TA010 (Sensor for Van). Both of these part numbers, along with their current known availability are also on the parts spreadsheet in the Sambar References section. I suggest checking that first if you have any other availability questions. The fan is just a 12v fan, I do not see why you could not check it with a multimeter, but I know of no writeups for videos on that.
Happen to know what temp the sensor is designed to trip on/off for the fan? Not seeing it in manual. Much appreciated.